JP2011228616A - Substrate transfer robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problems with a conventional transfer robot: the transfer robot transfers a plate-shaped substrate, such as a liquid crystal substrate, stored in a cassette using an equipped substrate detection sensor for detecting a position of the substrate, however, during this transfer process, the substrate stored in the cassette, being moved to frontward side (inlet side) of the cassette may be moved to the deep side to a degree, on which the transfer robot cannot take proper actions.SOLUTION: The transfer robot includes: a substrate detection sensor 5 for detecting the presence of a substrate attached near the front end of a hand 4; a transfer mechanism 11 (including arm mechanism 2) for moving a position of the hand; an operation control part 12 for controlling a position and a travel speed of the hand; and a substrate edge position analysis part 13 for calculating an edge position of a substrate. With such a configuration, a position of a substrate can be detected even when the substrate is moved to the deep side of a cassette for storage.

Description

  The present invention relates to a transfer robot for transferring a plate-like substrate such as a liquid crystal substrate.

  When carrying out a plate-like substrate such as a liquid crystal substrate accommodated in a cassette using a transfer robot, it is necessary to detect the position of the substrate. This is because the hand cannot grip the substrate if the relative position between the hand provided on the transfer robot and the position of the substrate deviates from an allowable value. For this reason, a substrate detection sensor for detecting the presence or absence of a substrate is attached to the transfer robot. And the position of a board | substrate is detected based on the detection signal output from a board | substrate detection sensor.

FIG. 12 is a schematic configuration diagram of a conventional transfer robot.
As shown in FIG. 12, the transfer robot 10 ′ is provided at the tip of the turning base 1, the lifting mechanism (not shown), the arm mechanism 2 including the first arm 2a and the second arm 2b, and the second arm 2b. A hand holder 3, a hand 7 attached to the hand holder 3, and a substrate detection sensor 8 for detecting the position of the substrate are schematically configured. The hand 7 includes a first hand 7a and a second hand 7b.

  Since the mechanism of the transfer robot 10 ′ is well known, the details are omitted, but as shown in FIG. 12A, the first arm 2a and the second arm 2b of the arm mechanism 2 are rotated. The hand 7 can be moved forward, and the hand 7 can be moved backward as shown in FIG. Further, it has a function of moving the arm mechanism 2 and the like up and down by a lifting mechanism (not shown). The hand 7 has a function of gripping the substrate. Therefore, the substrate can be carried into the cassette and the substrate can be carried out from the cassette by the transfer robot 10 '.

FIG. 13 is a configuration diagram of the substrate detection sensor.
The substrate detection sensor 8 is a non-contact type sensor and is attached to the sensor attachment member 9 as shown in FIG. And it has a function which detects the presence or absence of a board | substrate etc. by emitting a light ray etc. from a light projection part, reflecting it with the board | substrate etc. which are detection objects, and detecting with a light-receiving part. The detection signal of the substrate detection sensor 8 is output via a cable (not shown). In addition, commands to the substrate detection sensor 8 are also performed via a cable (not shown).

  In the conventional transfer robot 10 ′, the substrate detection sensor 8 is attached to the hand holder 3 or close to the hand holder 3 of the hand 7. That is, although there is a slight difference in position, the substrate detection sensor 8 is disposed in the vicinity of the hand holder 3 as shown in FIG. As the hand 7 moves, the position of the substrate detection sensor 8 also moves.

  FIG. 14 is a schematic plan view of the conventional transfer robot 10 ′ when the hand 7 is advanced and the hand 7 is moved into the cassette in order to carry out the substrate inside the cassette. In FIG. 14, a portion shown by a dotted line is a portion that passes through the inside of the cassette and is shown so that the positions of the hand 7, the substrate detection sensor 8, and the like are known.

  As shown in FIG. 14, the substrate has a plurality of sizes (for example, large size, medium size, and small size). In any case, the substrate is brought close to the front side (entrance side) of the cassette. It was housed inside the cassette. Therefore, when the hand 7 is moved into the cassette and the substrate is accommodated in the cassette, the substrate detection sensor 8 can be moved deeper than the edge position on the near side of the substrate.

FIG. 15 is a diagram for explaining the detection operation of the substrate detection sensor 8.
FIG. 15A shows a state in which the hand 7 is moved forward from the position where the hand 7 is retracted as shown in FIG. In this state, there is no substrate above the substrate detection sensor 8. Therefore, the light beam emitted from the light projecting unit of the substrate detection sensor 8 is not reflected by the substrate and cannot be detected by the light receiving unit. Therefore, it can be seen that there is no substrate.

  When the hand 7 of the transfer robot 10 ′ enters the cassette and there is a substrate above the substrate detection sensor 8 as shown in FIG. 15B, the light beam emitted from the light projecting portion of the substrate detection sensor 8, etc. Is reflected by the substrate and can be detected by the light receiving unit. More specifically, the amount of light detected by the light receiving unit increases and the amount of light becomes larger than the threshold value, so that it can be seen that there is a substrate.

  As shown in FIG. 15, the cassette usually has a multi-stage configuration in the vertical direction and can accommodate a plurality of substrates. However, only a part of the substrates is shown in FIG. The cassette is provided with a holding member for holding the substrate, but the illustration is omitted.

JP 2006-273524 A

  As described above, conventionally, as shown in FIG. 14, the substrate has been brought close to the front side (entrance side) of the cassette and accommodated in the cassette. Therefore, when the hand 7 is moved into the cassette, if the substrate is accommodated in the cassette, the presence or absence of the substrate can be detected by the substrate detection sensor 8. However, recently, there has been a case where the substrate is not necessarily moved toward the front side of the cassette, and as shown in FIG. 16, the substrate is moved closer to the back side of the cassette.

  In this case, the position of the substrate cannot be detected unless the hand 7 is inserted deeper into the cassette than in the prior art. However, since the hand holder 3 of the transfer robot 10 ′ is thick, it is difficult to move the hand 7 to the back side of the cassette as compared with the conventional case. This is because the hand holder 3 may collide with another substrate or the like. In other words, the conventional transfer robot 10 'cannot cope with the case where the substrate is moved to the back side of the cassette as shown in FIG.

  The present invention has been conceived under the above circumstances, and provides a transfer robot that can detect the position of a substrate even when the substrate is housed near the back of a cassette. It is an object.

The substrate transfer robot provided by the first invention is:
Using a hand for holding a substrate, a substrate transfer robot for carrying a plate-like substrate into and out of a cassette is targeted,
A hand for holding the substrate;
A hand holder for supporting the proximal end of the hand;
A substrate detection sensor for detecting the presence or absence of a substrate attached to or near the tip of the hand; and
A moving mechanism for moving the position of the hand;
A control unit for controlling the position and moving speed of the hand;
A substrate edge position analysis unit that calculates an edge position of the substrate based on the detection signal of the substrate detection sensor and information on the position of the substrate detection sensor output from the control unit;
It is characterized by having.

In the substrate transfer robot provided by the second invention, the control unit includes:
Based on information on the cassette and the substrate given in advance, a function for obtaining a cassette entry position that allows the hand to pass under the substrate to be detected and move in the back direction of the cassette;
A function of controlling a moving mechanism so that the hand moves to the cassette entry position;
A function of estimating the edge position of the back side of the substrate accommodated in the cassette, based on the prescribed position information of the substrate given in advance or the prescribed position information of the substrate obtained by calculation,
When the direction from the cassette entry position toward the back side of the cassette is set as a reference direction, the hand is advanced at a predetermined speed along the reference direction, and the hand enters the cassette. A function of controlling the moving mechanism so that the substrate detection sensor provided in the front end portion of the hand or in the vicinity of the front end portion moves to the back side of the cassette;
When the substrate detection sensor that moves together with the hand reaches a position in front of the estimated distance from the same position in the reference direction by a predetermined distance, the moving speed of the hand is reduced. A function to control the moving mechanism,
A function of controlling the movement mechanism so that the substrate detection sensor moves to a predetermined position on the back side of the cassette from the same position in the reference direction as the estimated edge position on the back side of the substrate;
Based on the edge position of the back side of the substrate obtained by the substrate edge position analysis unit, a function of calculating the amount of positional deviation of the substrate on the reference direction including the position where the substrate detection sensor is attached;
Based on the calculated amount of positional deviation of the substrate on the reference direction, a function for correcting and calculating the hand position when gripping the substrate;
A function of controlling the moving mechanism so that the hand moves to the corrected hand position;
It is characterized by having.

The substrate transfer robot provided by the third invention is:
The substrate edge position analysis unit,
The position information of the substrate detection sensor and the detection signal of the substrate detection sensor are stored, and the detection signal of the substrate detection sensor changes from the state indicating the presence of the substrate to the state indicating the absence of the substrate, and indicates the absence of the substrate. When the state continues for a predetermined confirmation distance, the position of the substrate detection substrate detection sensor at that time is set as a reference position, and the position on the near side of the cassette is set to the back side of the substrate by the confirmation distance from the reference position. It is characterized by analyzing as an edge position.

The substrate transfer robot provided by the fourth invention is:
The substrate edge position analysis unit,
The position information of the substrate detection sensor and the detection signal of the substrate detection sensor are stored, and the detection signal of the substrate detection sensor changes from the state indicating the presence of the substrate to the state indicating the absence of the substrate, and indicates the absence of the substrate. When the state continues for a predetermined confirmation time, the position of the substrate detection sensor that is past the confirmation time from that time is analyzed as the edge position on the back side of the substrate.

The substrate transfer robot provided by the fifth invention is:
The substrate edge position analysis unit,
A storage unit for storing position information of the substrate detection sensor and a detection signal of the substrate detection sensor;
Based on the data stored in the storage unit, an analysis unit for analyzing the edge position of the back side of the substrate,
It is characterized by having.

The substrate transfer robot provided by the sixth invention is:
A plurality of hands are provided, and two or more of these hands are provided with the substrate detection sensor. Also,
The substrate edge position analysis unit,
A storage unit for storing the positional information of each substrate detection sensor and the detection signal of each substrate detection sensor in association with each other;
Based on the data stored in the storage unit, an analysis unit that analyzes the edge position of the back side of the substrate on the reference direction including the position where each substrate detection sensor is attached,
It is characterized by having.

The substrate transfer robot provided by the seventh invention is:
The substrate detection sensor is attached so as to be embedded in the hand.

The substrate transfer robot provided by the eighth invention provides:
When the hand is moved to the back side of the cassette, the length of the hand is set so that the position of the substrate detection sensor is located on the back side of the back side edge position of the substrate. It is a feature.

The substrate transfer robot provided by the ninth invention is:
Further, an auxiliary hand having a base end supported by the hand holder and shorter in length than the hand is further provided on the outer side of the hand holder than the hand.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where a board | substrate is brought close to the back | inner side of a cassette and accommodated, the conveyance robot which can detect the position of a board | substrate can be provided.

1 is a diagram illustrating a schematic configuration of a transfer robot 10 according to a first embodiment. It is a figure which shows the example of arrangement | positioning of the light projection part of the board | substrate detection sensor 5, and a light-receiving part. FIG. 3 is a schematic plan view when the transfer robot according to the first embodiment advances the hand 4 and moves the hand 4 into the cassette in order to carry out the substrate inside the cassette. It is a figure which shows the light quantity detected by the light-receiving part of the board | substrate detection sensor 5 in the process in which the board | substrate detection sensor 5 advances from the near side of a board | substrate to the back side. FIG. 6 is an image diagram showing a relationship between a position of a substrate and a light amount detected by a light receiving unit of the substrate detection sensor 5. It is a figure which shows the speed pattern at the time of the board | substrate detection sensor 5 passing the lower side of a board | substrate. It is a functional block diagram which shows the function with which the conveyance robot 10 which concerns on 1st Embodiment is provided. It is a figure which shows an example in case the board | substrate has shifted | deviated left-right asymmetric with respect to the reference direction. It is a figure which shows schematic structure of the conveyance robot 10a which concerns on 2nd Embodiment. It is a figure which shows an example of the turning radius of the conveyance robot 10a. It is a figure which shows the length of the auxiliary hand 6 in the longitudinal direction. It is a schematic block diagram of the conventional conveyance robot. It is a block diagram of a board | substrate detection sensor. FIG. 10 is a schematic plan view of the conventional transfer robot 10 ′ when the hand 7 is moved forward to enter the cassette in order to carry out the substrate inside the cassette. It is a figure for demonstrating the detection operation of the board | substrate detection sensor. It is a figure which shows the case where a board | substrate is brought close to the back side of a cassette.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is a diagram illustrating a schematic configuration of a transfer robot 10 according to the first embodiment. In addition, the same code | symbol is attached | subjected to the same or similar element as the past.
As shown in FIG. 1, the transfer robot 10 includes a swing base 1, an elevating mechanism (not shown), an arm mechanism 2 including a first arm 2a and a second arm 2b, and a hand holder provided at the tip of the second arm 2b. 3. A base end portion is roughly constituted by a hand 4 attached to the hand holder 3 and a substrate detection sensor 5 for detecting the presence or absence of a substrate attached to the distal end portion (or the vicinity of the distal end portion) of the hand 4. The hand 4 includes a first hand 4a and a second hand 4b. The substrate detection sensor 5 includes a first substrate detection sensor 5a and a second substrate detection sensor 5b. Then, the position of the substrate is detected based on the detection signal output from the substrate detection sensor 5. Moreover, it is not limited to the above structure. For example, the number of hands 4 and the number of substrate detection sensors 5 may be different from the above.

  One end of the first arm 2a is connected to the turning base 1 and is rotated around a vertical connecting axis L1. One end of the second arm 2b is connected to the other end of the first arm 2a, and the second arm 2b is rotated around a vertical connection axis L2. The hand holder 3 is connected to the other end of the second arm 2b, and is attached to be rotatable around a vertical connecting axis L3. Further, a motor, a pulley, etc. (not shown) are used to operate the arm mechanism 2 of the transfer robot 10 and to move it up and down.

  Since the mechanism of the transfer robot 10 is well known, the details are omitted. However, the first transfer mechanism 2 described above with reference to FIG. Similar to the robot 10, the hand 4 is moved forward / backward, and the arm mechanism 2 is moved up and down by a lifting mechanism (not shown). The hand 4 has a function of gripping the substrate. Therefore, the substrate can be carried into the cassette and the substrate can be carried out from the cassette by the transfer robot 10. Note that there is a transfer robot 10 that does not include an elevating mechanism when an elevating mechanism is provided on the cassette side.

  The substrate detection sensor 5 is a non-contact type sensor that emits a light beam or the like from a light projecting unit, reflects it by a substrate or the like that is a detection target, and detects the presence or absence of a substrate or the like by detecting it with a light receiving unit. It has a function to detect. The detection signal of the substrate detection sensor 5 is output via a cable (not shown). In addition, commands to the substrate detection sensor 5 are also performed via a cable (not shown). The substrate detection sensor 5 is the same as the prior art described with reference to FIG. 13, but in this embodiment, as shown in FIG. 1, the substrate detection sensor 5 is located at the tip of the hand 4 (or in the vicinity of the tip). Embedded in.

  There are various types of non-contact type substrate detection sensors 5, for example, there are a type using a laser beam, a type using a light emitting diode, a type using an ultrasonic wave, etc., which are optimal depending on the purpose and situation. The type is selected. In addition to the function of detecting the presence or absence of a substrate or the like, there is a type that can measure the distance between the substrate detection sensor 5 and the substrate or the like, but it is sufficient to use at least a function that detects the presence or absence of a substrate or the like. .

  In addition, for example, there may be a case where there is no substrate to be detected in a cassette configured to accommodate substrates in multiple stages, and there is a substrate on the upper stage. In consideration of such a case, a type with a short detection distance of the substrate detection sensor 5 may be selected so that the upper substrate is not erroneously detected.

FIG. 2 is a diagram illustrating an arrangement example of the light projecting unit and the light receiving unit of the substrate detection sensor 5.
As shown in FIGS. 2A and 2B, the light projecting unit and the light receiving unit of the substrate detection sensor 5 are arranged in series with respect to the traveling direction of the hand 4 (vertical in the drawing). 2), and as shown in FIG. 2C, the light projecting unit and the light receiving unit may be arranged in parallel (lateral direction in the drawing) with respect to the traveling direction of the hand 4.

  FIG. 3 is a schematic plan view of the transport robot 10 according to the first embodiment when the hand 4 is advanced and the hand 4 enters the cassette in order to carry out the substrate inside the cassette. In FIG. 3, a portion shown by a dotted line is a portion that passes through the inside of the cassette and is shown so that the positions of the hand 4, the substrate detection sensor 5, and the like are known.

  As shown in FIG. 3, the substrate has a plurality of sizes (for example, a large size, a medium size, and a small size). In any case, the substrate is moved to the back side of the cassette and accommodated in the cassette. Shows the case. As shown in FIG. 3, even when the substrate is moved to the back side of the cassette and accommodated in the cassette, when the hand 4 is moved to the back side of the cassette, the tip of the hand 4 The length of the hand 4 is set so that the position of the substrate detection sensor 5 provided in (or in the vicinity of the front end) is located on the back side of the back edge position of the substrate. Therefore, even if the substrate is brought closer to the back side of the cassette and accommodated in the cassette, the back edge position of the substrate can be detected based on the detection signal of the substrate detection sensor 5. In this specification, the direction from the cassette entry position toward the back side of the cassette is defined as a reference direction (or front-rear direction). A direction perpendicular to the reference direction in the horizontal plane is defined as the left-right direction.

  FIG. 4 is a diagram illustrating the amount of light detected by the light receiving unit of the substrate detection sensor 5 in the process in which the substrate detection sensor 5 proceeds from the front side to the back side of the substrate. However, FIG. 4 is a diagram showing an ideal detection signal. In practice, there is a problem that the amount of light is not constant as will be described later. First, the detection operation of the substrate detection sensor 5 in an ideal state is described. Explain.

  As shown in FIG. 4, when there is no substrate above the substrate detection sensor 5, the light quantity detected by the light receiving unit does not reach the threshold value, so “no substrate” is detected. Further, when there is a substrate above the substrate detection sensor 5, the amount of light detected by the light receiving unit is equal to or greater than a threshold value, so that “substrate is present” is detected. That is, when the substrate detection sensor 5 is provided at the front end portion of the hand 4 as in the present embodiment and the hand 4 is advanced from the front side to the back side of the cassette, ideally, as shown in FIG. It changes from “no board” to “with board” at the edge on the front side of the board, and after that, while the board detection sensor 5 is passing the lower side of the board, the state of “with board” is maintained. The output of the substrate detection sensor 5 changes from “with substrate” to “without substrate” at the back edge position.

  In this way, if the substrate detection sensor 5 is attached to the tip of the hand 4, even if the substrate is disposed on the back side of the cassette, the presence or absence of the substrate is detected based on the detection signal of the substrate detection sensor 5. Can do. As a result, the edge position of the substrate can be detected. However, due to the following problems, the edge position cannot be detected in an ideal state as shown in FIG.

[Problem 1]
FIG. 5 is an image diagram showing the relationship between the position of the substrate and the amount of light detected by the light receiving unit of the substrate detection sensor 5.
In the case of a liquid crystal substrate, since the substrate pattern is not stacked on the end portion (near the edge) of the substrate, the end portion of the substrate remains as raw glass. Therefore, the reflectance remains low as the process proceeds. Therefore, as shown in FIG. 5, the amount of light detected by the light receiving unit at the edge position is actually smaller than the amount of light in other portions. In addition, although a deposit may be attached as the process proceeds, the amount of light detected by the light receiving unit at the edge position is still small. Hereinafter, the near side and the far side of the substrate will be described.

(1) About the front side of the board Even when the board detection sensor 5 reaches the edge position on the front side of the board, the amount of light detected by the light receiving unit does not reach the threshold value, and “no board” is detected. There is. Thereafter, as the hand 4 advances to the back side, the amount of light detected by the light receiving unit increases. That is, the edge position cannot be detected with high accuracy.

(2) About the back side of the board On the back side of the board, the amount of light detected by the light receiving unit decreases even though it has not yet reached the edge position on the back side of the board. May end up. That is, the edge position cannot be detected with high accuracy. Note that FIG. 5 illustrates an example in which “there is a substrate” is detected because the amount of light decreases near the edge position on the far side, but is larger than the threshold value.

[Problem 2]
The tip of the hand 4 is more susceptible to vibration than the base (base end) of the hand 4. And if a vibration arises, since a detected value will become unstable, an erroneous detection will be caused. Usually, in order to shorten the conveyance time, the hand 4 is moved as fast as possible. If it becomes so, it will be easy to produce a vibration and a detection value will become unstable easily.

[Problem 3]
The raw glass before the process (before processing) has a low transmittance because of its high transmittance, but the reflectance increases as a pattern is generated on the substrate as the process proceeds. That is, the reflectance varies depending on the progress of the process. In addition, not all portions of the substrate have the same reflectance, and the reflectance may vary depending on the portion. Furthermore, the vibration of the hand 4 described above may affect the reflectance. Therefore, depending on the location of the substrate, the amount of received light is reduced despite the presence of the substrate, and there is a risk of erroneous detection if there is no substrate. That is, there is a possibility that a place other than the edge position is erroneously detected as the edge position. FIG. 5 shows an example in which a false distance d1 (minute time t1) is erroneously detected at a location other than the edge position.

  Therefore, in this embodiment, the following measures are taken to solve the above problem.

[Countermeasure for Problem 1]
Since the substrate detection sensor 5 passes directly under the substrate, if it is a reflection type sensor, it has a certain amount of received light and can sufficiently detect the presence or absence of the substrate. Even in the conventional transfer robot 10 ′, it can be seen that there is no problem in detecting the edge portion because the edge of the substrate can be detected. That is, there is a difference between whether the edge position on the near side of the substrate is detected as in the conventional transfer robot 10 ′ or the edge position on the back side of the substrate is detected as in the present embodiment. Similarly to 10 ', if the moving speed when the substrate detection sensor 5 reaches just below the edge position on the back side of the substrate to be detected is slow, the change in the presence or absence of the substrate is detected at the edge position. Can do.
In addition, when the board | substrate detection sensor 5 is provided in the front-end | tip part (or front-end | tip part vicinity) of the hand 4 like this embodiment, when the board | substrate detection sensor 5 passes just under the edge position of the near side of a board | substrate. In order to shorten the tact time, the moving speed of the hand 4 cannot be slowed down. Therefore, it is not suitable for detecting the edge position on the near side of the substrate.

[Countermeasure for Problem 2]
The edge position to be detected is the edge position on the back side of the substrate. Therefore, as shown in FIG. 6, if the position of the substrate detection sensor 5 starts to decelerate somewhat before the edge position on the back side of the substrate, the substrate detection sensor 5 moves directly below the edge position on the back side. The vibration of the hand 4 when passing is reduced, and the edge of the substrate can be sufficiently detected.

  Here, information on the size of the substrate and information on whether or not the substrate is arranged on the back side of the cassette are given in advance. By calculating based on this information, the specified value (specified position) of the edge position on the back side of the substrate can be known. Alternatively, the specified value of the edge position on the back side of the substrate may be directly given. That is, the specified value of the edge position on the back side of the substrate can be directly or indirectly known. However, since the actual substrate placement position varies, it does not follow the specified value. Therefore, provisionally, the specified value of the edge position on the back side of the substrate is adopted as the estimated value (estimated position) of the edge position on the back side of the substrate.

  Further, as described above, since there are variations in the arrangement position of the substrates, the position at which deceleration is started may be determined in consideration of the variation. For example, suppose that the user wants to decelerate from 100 mm before the estimated value (specified value) of the edge position on the back side of the substrate. Then, it is assumed that the variation in the arrangement position of the substrate is ± 20 mm. In this case, considering the variation, the speed may be decelerated from 120 mm before the rear edge position (specified value).

  In the conventional transfer robot 10 ', the mounting position of the substrate detection sensor 5 is different. However, since the same speed control is performed, the tact time is hardly affected from the viewpoint of comparison with the prior art. Absent.

[Countermeasure for Problem 3]
Even with respect to the problem of detecting a position other than the edge (for example, near the center of the substrate) as the edge position, the problem can be solved by slowing the moving speed of the hand 4. The tact time is delayed, which is a problem. Therefore, a solution different from the moving speed of the hand 4 is desired.
Therefore, paying attention to the fact that there is little possibility of detecting a part other than an edge as an edge, even if a false detection occurs, it is only a part of the part and does not continue. . Therefore, the edge position may be determined only when the state detected that there is no substrate continues. The determination criterion in this case may be a case where “none” continues for a predetermined distance, or a case where “none” continues for a predetermined time. Of course, since it has gone too far from the edge position of the substrate in the meantime, the position obtained by subtracting that amount may be set as the edge position of the substrate. Further, since the position of the cassette is also known, the position is controlled so that the hand 4 does not collide with the cassette.

  By taking the above measures, the presence / absence of the substrate can be detected based on the detection signal of the substrate detection sensor 5 even if the substrate is arranged on the back side of the cassette. As a result, the edge position of the substrate can be detected. If the edge position of the substrate is known, the hand position when the substrate is held can be corrected and calculated.

FIG. 7 is a functional block diagram showing functions provided in the transfer robot 10 according to the first embodiment.
As shown in FIG. 7, in order to realize the above countermeasure, this embodiment includes a moving mechanism 11, an operation control unit 12, and a substrate edge position analysis unit 13 when viewed from the functional aspect.

  The moving mechanism 11 is a mechanism that moves the position of the hand 4. In the present embodiment, a mechanism including the arm mechanism 2 mainly including the first arm 2a and the second arm 2b is illustrated, but the transfer robot 10 illustrated in the present embodiment is merely an example, and the position of the hand 4 Any mechanism may be used as long as it moves. For example, an elevating mechanism may or may not be provided. Further, a motor or the like (not shown) is also included in the moving mechanism 11. In addition, the hand holder 3 connected to the second arm 2 b is also included in the moving mechanism 11.

  The substrate edge position analysis unit 13 receives the position information of the substrate detection sensor 5 and the detection signal of the substrate detection sensor 5 input from the operation control unit 12 described later, and analyzes the edge position on the back side of the substrate ( Sought). The substrate edge position analysis unit 13 includes a storage unit 14 and an analysis unit 15.

  The storage unit 14 stores the positional information input from the operation control unit 12 and the detection signal of the substrate detection sensor 5 in association with each other.

The analysis unit 15 analyzes (determines) the edge position on the back side of the substrate based on the data stored in the storage unit 14.
Specifically, the data stored in the storage unit 14 is read, the detection signal of the substrate detection sensor 5 changes from the state indicating the presence of the substrate to the state indicating the absence of the substrate, and the state indicating the absence of the substrate is predetermined. When the check distance continues, the position of the substrate detection sensor 5 at that time is used as a reference position, and the position on the near side of the cassette as viewed from the reference position is determined as the edge position on the back side of the substrate.

  Since we know the sampling time of the data, we can do the following: That is, the substrate edge position analysis unit 13 reads the data stored in the storage unit 14, and the detection signal of the substrate detection sensor 5 changes from the state indicating the presence of the substrate to the state indicating the absence of the substrate, and indicates the absence of the substrate. When the state continues for a predetermined confirmation time, the position of the substrate detection sensor 5 in the past for the confirmation time from that time is obtained as the edge position on the back side of the substrate.

  When the edge position on the back side of the substrate obtained by the substrate edge position analysis unit 13 is greatly deviated from the specified value (specified position), that is, when there is a deviation greater than a preset allowable value. It can be determined that it is abnormal. At that time, processing such as stopping the operation of gripping the substrate by the hand 4 can be performed.

  Further, when the detection target substrate is not accommodated in the cassette, the detection signal of the substrate detection sensor 5 remains in a state indicating that there is no substrate, and thus it is understood that there is an abnormality. Even at that time, it is possible to perform processing such as stopping the operation of gripping the substrate by the hand 4.

By the way, as described above, in the transfer robot 10 according to the present embodiment, the hand 4 is configured by the first hand 4a and the second hand 4b, and the first substrate detection sensor 5a is provided at each tip. And since the 2nd board | substrate detection sensor 5b is provided, the rotation shift | offset | difference of a board | substrate is detectable. Here, assuming that the substrate detection sensor provided in the first hand 4a is the first substrate detection sensor 5a and the substrate detection sensor provided in the second hand 4b is the second substrate detection sensor 5b, FIG. As described above, it is possible to detect not only the shift in the reference direction but also whether the substrate is shifted asymmetrically with respect to the reference direction.
For example, it is detected that the first substrate detection sensor 5a is displaced by 5 mm in the forward direction of the hand with respect to the reference direction with respect to the specified value (specified position) of the edge position on the back side of the substrate. Assume that it is detected that the substrate detection sensor 5b is displaced by 10 mm in the forward direction of the hand with respect to the reference direction. Then, it can be seen that the substrate is shifted asymmetrically with respect to the reference direction.

  Therefore, based on the edge position on the back side of the substrate obtained by the substrate edge position analysis unit 13, it is possible to calculate the amount of displacement of the substrate with reference to the specified value (specified position) in the reference direction. This calculation is performed by the operation control unit 12. For this purpose, as shown in FIG. 7, the edge position on the back side of the substrate obtained by the substrate edge position analysis unit 13 (more specifically, the analysis unit 15 described later) is input to the operation control unit 12.

  In addition, since the distance between the first substrate detection sensor 5a and the second substrate detection sensor 5b is known, the displacement angle (angle displacement amount) of the substrate can be calculated. For this reason, if two substrate detection sensors can be used to calculate the amount of displacement of the substrate in the reference direction including the position where each substrate detection sensor is mounted, the displacement angle (angular displacement amount) of the substrate is further calculated. can do. Therefore, it is possible to correct and calculate the hand position when holding the substrate in consideration of the displacement angle (angle displacement amount) of the substrate. Then, the moving mechanism 11 may be controlled so that the hand 4 moves to the corrected hand position.

  When three or more substrate detection sensors are used, a substrate shift angle (angle shift amount) may be calculated based on detection signals of at least two or more substrate detection sensors.

The operation control unit 12 is a control unit that performs position control and speed control of the moving mechanism 11.
The moving mechanism 11 moves the hand 4 based on the command of the operation control unit 12. Further, the position information of the substrate detection sensor 5 attached to the hand 4 is output to the substrate edge position analysis unit 13 (more specifically, a storage unit 14 described later). The operation control unit 12 also has the following functions.

(1) Based on information about the cassette and the substrate given in advance, a cassette entry position is calculated (calculated) so that the hand 4 can pass under the substrate to be detected and move in the back side of the cassette. )function.
(2) A function of controlling the moving mechanism 11 so that the hand 4 moves to the entry position.
(3) A function of estimating the edge position of the back side of the substrate accommodated in the cassette based on the predetermined position information of the substrate given in advance or the specified position information of the substrate obtained by calculation.
(4) When the direction from the cassette entry position toward the back side of the cassette is the reference direction, the hand 4 is advanced at a predetermined speed along the reference direction. And the function which controls the moving mechanism 11 so that the board | substrate detection sensor 5 provided in the front-end | tip part of the hand 4 moves to the back | inner side of a cassette by making the said hand 4 approach in a cassette.
(5) When the substrate detection sensor 5 moving together with the hand 4 reaches a position in front of the estimated distance from the same position in the reference direction by a predetermined distance, the moving speed of the hand is A function that controls the moving mechanism to decelerate.
(6) For example, a function of controlling the moving mechanism so that the substrate detection sensor 5 moves to a predetermined position on the back side of the cassette from the same position in the reference direction as the estimated edge position on the back side of the substrate. .
(7) A function for calculating the amount of positional deviation of the substrate in the reference direction including the position where the substrate detection sensor is attached, based on the edge position on the back side of the substrate obtained by the substrate edge position analysis unit 13.
In order to realize this function, as shown in FIG. 7, the edge position on the back side of the substrate obtained by the substrate edge position analysis unit 13 (more specifically, an analysis unit 15 described later) is used as the operation control unit 12. To enter.
(8) A function of correcting and calculating the hand position when gripping the substrate based on the calculated amount of displacement of the substrate in the reference direction.
(9) A function of controlling the moving mechanism 11 so that the hand 4 moves to the hand position that has been corrected and calculated.

  By having the above function, if it is within an allowable range, even if there is a positional deviation of the substrate, the positional deviation relative to the reference direction and the angular deviation of the substrate can be corrected. In this way, when the substrate is transported to the next place by the transport robot 10, the alignment step for correcting the positional deviation with respect to the reference direction and the angular deviation of the substrate can be omitted.

[Second Embodiment]
FIG. 9 is a diagram showing a schematic configuration of a transfer robot 10a according to the second embodiment.
The transfer robot 10a is further provided with an auxiliary hand 6 (first auxiliary hand 6a, second auxiliary hand 6b) as compared with the transfer robot 10 shown in FIG. Other configurations are the same as those of the transfer robot 10 shown in FIG. In addition, the same code | symbol is attached | subjected to the element which is the same as that of 1st Embodiment, or similar.

  That is, as shown in FIG. 9, the transfer robot 10a is provided at the tip of the turning base 1, the lifting mechanism (not shown), the arm mechanism 2 including the first arm 2a and the second arm 2b, and the second arm 2b. The hand holder 3, the hand 4 whose base end is attached to the hand holder 3, the substrate detection sensor 5 for detecting the presence or absence of a substrate attached to the front end (or the vicinity of the front end) of the hand 4, and the base end are the hand The auxiliary hand 6 attached to the holder 3 is schematically configured.

  The hand 4 includes a first hand 4a and a second hand 4b. The substrate detection sensor 5 includes a first substrate detection sensor 5a and a second substrate detection sensor 5b. The auxiliary hand 6 includes a first auxiliary hand 6a and a second auxiliary hand 6b. Then, the position of the substrate is detected based on the detection signal output from the substrate detection sensor 5. Moreover, it is not limited to the above structure. For example, the number of hands 4, the number of substrate detection sensors 5, and the number of auxiliary hands 6 may be different from the above.

  By the way, as shown in FIG. 9, the length of the auxiliary hand 6 in the longitudinal direction is shorter than the length of the hand 4 in the longitudinal direction. The reason for this will be described with reference to FIGS.

  FIG. 10 is a diagram illustrating an example of the turning radius of the transfer robot 10a. More specifically, FIG. 10 is a diagram illustrating a state in which the hand 4 of the transfer robot 10a is moved backward so that the turning radius when the entire transfer robot 10a is rotated around the connection axis L1 is as small as possible. is there. That is, FIG. 10 shows a state in which the minimum turning radius can be obtained when the hand 4 is provided at the positions of the first hand 4a1 and the second hand 4b1 illustrated by solid lines. The turning radius at this time is R1. The first hand 4a1 is provided with a first substrate detection sensor 5a1, and the second hand 4b1 is provided with a second substrate detection sensor 5b1.

  Further, in FIG. 10, a state in which the positions of the first hand 4a1 and the second hand 4b1 are respectively shifted outward in the left-right direction is illustrated as a first hand 4a2 and a second hand 4b2 illustrated by dotted lines. . And it shows that the turning radius in this state is R2. It is assumed that the first hand 4a2 is provided with a first substrate detection sensor 5a2, and the second hand 4b2 is provided with a second substrate detection sensor 5b2.

  Strictly speaking, the turning radius R2 in the state of the first hand 4a2 and the second hand 4b2 illustrated by the dotted lines is not the minimum turning radius, but the turning becomes shorter as the distance between the tip of the hand 4 and the connecting shaft L1 is shorter. It can be seen that the radius can be reduced. In the example of FIG. 10, R1 <R2, and the closer the position of the hand 4 is to the center of the hand holder 3, the shorter the distance between the tip of the hand 4 and the connecting shaft L <b> 1, indicating that the turning radius can be reduced. Yes. That is, it is shown that the turning radius can be reduced as the position of the base end portion of the hand 4 is brought closer to the center of the hand holder 3.

In the present embodiment, as described above, even when the substrate is moved to the back side of the cassette and accommodated inside the cassette, when the hand 4 is moved to the back side of the cassette, The length of the hand 4 is set so that the position of the substrate detection sensor 5 provided at the distal end portion (or the vicinity of the distal end portion) is located on the back side with respect to the back side edge position of the substrate. That is, the length of the hand 4 is longer than the minimum length necessary for holding the substrate. Therefore, the turning radius tends to be slightly larger than before.
Therefore, from the viewpoint of the turning radius, it is preferable to make the minimum turning radius as small as possible by bringing the position of the base end portion of the hand 4 closer to the center of the hand holder 3.

  However, from the viewpoint of holding the substrate, if the position of the base end portion of the hand 4 is too close to the center of the hand holder 3, the stability when holding the substrate is lowered. Therefore, as shown in FIG. 9, in the left-right direction, the auxiliary hand 6 whose base end is supported by the hand holder at a position outside the first hand 4 a and the second hand 4 b (a position closer to the outside). By further providing (the first auxiliary hand 6a and the second auxiliary hand 6b), the stability when holding the substrate is improved.

  As described above, since the displacement angle (angular displacement amount) of the substrate is calculated, it is necessary to secure a certain distance between the first substrate detection sensor 5a and the second substrate detection sensor 5b. Therefore, even when the auxiliary hand 6 is provided, it is necessary to secure a certain distance between the first hand 4a and the second hand 4b.

  That is, the position of the base end portion of the hand 4 is set to the center of the hand holder 3 while ensuring the distance between the first hand 4a and the second hand 4b to such an extent that the deviation angle (angle deviation amount) of the substrate can be calculated. It is possible to make the minimum turning radius as small as possible. Moreover, the stability when holding a board | substrate can be improved by providing the auxiliary hand 6 (1st auxiliary hand 6a, 2nd auxiliary hand 6b) as needed.

  However, as shown in FIG. 11, the length in the longitudinal direction of the auxiliary hand 6 (the first auxiliary hand 6 a and the second auxiliary hand 6 b) is shorter than the length in the longitudinal direction of the hand 4. More specifically, the length of the auxiliary hand 6 in the longitudinal direction is set so as to be within the minimum turning radius R.

  In the above description, the arm-type transfer robot 10 has been described as an example. However, the transfer robot 10 is not limited to this type, and other types of transfer robots 10 may be used. For example, it may be a slide type transfer robot instead of an arm type, or may be a transfer robot using both an arm and a slide mechanism. Moreover, the conveyance robot which is not provided with a raising / lowering mechanism may be sufficient, and the conveyance robot provided with 2 sets of arm mechanisms 2 may be sufficient. In short, any transfer robot 10 may be used as long as the substrate detection sensor 5 can be attached to the tip (or the vicinity of the tip) of the hand that can move in the horizontal direction.

  In the above description, the hand 4 has been described with two forms on the left and right as an example, but the present invention is not limited to such a form. For example, one hand 4 or three or more hands 4 may be used. However, the angle shift cannot be detected with the single hand 4.

  Further, the shape of the hand 4 is not limited to the illustrated example, and for example, the hand 4 including an auxiliary body that supports the substrate in the left-right direction of the hand 4 may be used.

DESCRIPTION OF SYMBOLS 1 Turning base 2a 1st arm 2b 2nd arm 2 Arm mechanism 3 Hand holder 4 Hand 5 Substrate detection sensor 5a Substrate detection sensor 5b Substrate detection sensor 6 Auxiliary hand 7 Hand 7a Hand 7b Hand 8 Substrate detection sensor 9 Sensor attachment member 10 Conveyance Robot 11 Movement mechanism 12 Operation control unit 13 Substrate edge position analysis unit 14 Storage unit 15 Analysis unit L1 Connection axis L2 Connection axis L3 Connection axis

Claims (9)

In a substrate transfer robot for carrying a plate-like substrate into and out of a cassette using a hand for holding the substrate,
A hand for holding the substrate;
A hand holder for supporting the proximal end of the hand;
A substrate detection sensor for detecting the presence or absence of a substrate attached to or near the tip of the hand; and
A moving mechanism for moving the position of the hand;
A control unit for controlling the position and moving speed of the hand;
A substrate edge position analysis unit that calculates an edge position of the substrate based on the detection signal of the substrate detection sensor and information on the position of the substrate detection sensor output from the control unit;
A substrate transfer robot comprising: The controller is
Based on information on the cassette and the substrate given in advance, a function for obtaining a cassette entry position that allows the hand to pass under the substrate to be detected and move in the back direction of the cassette;
A function of controlling a moving mechanism so that the hand moves to the cassette entry position;
A function of estimating the edge position of the back side of the substrate accommodated in the cassette, based on the prescribed position information of the substrate given in advance or the prescribed position information of the substrate obtained by calculation,
When the direction from the cassette entry position toward the back side of the cassette is set as a reference direction, the hand is advanced at a predetermined speed along the reference direction, and the hand enters the cassette. A function of controlling the moving mechanism so that the substrate detection sensor provided in the front end portion of the hand or in the vicinity of the front end portion moves to the back side of the cassette;
When the substrate detection sensor that moves together with the hand reaches a position in front of the estimated distance from the same position in the reference direction by a predetermined distance, the moving speed of the hand is reduced. A function to control the moving mechanism,
A function of controlling the movement mechanism so that the substrate detection sensor moves to a predetermined position on the back side of the cassette from the same position in the reference direction as the estimated edge position on the back side of the substrate;
Based on the edge position of the back side of the substrate obtained by the substrate edge position analysis unit, a function of calculating the amount of positional deviation of the substrate on the reference direction including the position where the substrate detection sensor is attached;
Based on the calculated amount of positional deviation of the substrate on the reference direction, a function for correcting and calculating the hand position when gripping the substrate;
A function of controlling the moving mechanism so that the hand moves to the corrected hand position;
The substrate transfer robot according to claim 1, comprising: The substrate edge position analysis unit
The position information of the substrate detection sensor and the detection signal of the substrate detection sensor are stored, and the detection signal of the substrate detection sensor changes from the state indicating the presence of the substrate to the state indicating the absence of the substrate, and indicates the absence of the substrate. When the state continues for a predetermined confirmation distance, the position of the substrate detection substrate detection sensor at that time is set as a reference position, and the position on the near side of the cassette is set to the back side of the substrate by the confirmation distance from the reference position. The substrate transfer robot according to claim 1, wherein the substrate transfer robot is analyzed as an edge position. The substrate edge position analysis unit
The position information of the substrate detection sensor and the detection signal of the substrate detection sensor are stored, and the detection signal of the substrate detection sensor changes from the state indicating the presence of the substrate to the state indicating the absence of the substrate, and indicates the absence of the substrate. 2. When the state continues for a predetermined confirmation time, the position of the substrate detection sensor that is past the confirmation time from that time is analyzed as an edge position on the back side of the substrate. 4. The substrate transfer robot according to any one of 3. The substrate edge position analysis unit
A storage unit for storing position information of the substrate detection sensor and a detection signal of the substrate detection sensor;
Based on the data stored in the storage unit, an analysis unit for analyzing the edge position of the back side of the substrate,
The substrate transport robot according to claim 1, comprising: A plurality of the hands are provided, and the substrate detection sensor is provided in two or more of the hands,
The substrate edge position analysis unit
A storage unit for storing the positional information of each substrate detection sensor and the detection signal of each substrate detection sensor in association with each other;
Based on the data stored in the storage unit, an analysis unit that analyzes the edge position of the back side of the substrate on the reference direction including the position where each substrate detection sensor is attached,
The substrate transport robot according to claim 1, comprising:   The substrate transfer robot according to claim 1, wherein the substrate detection sensor is attached so as to be embedded in the hand.   When the hand is moved to the back side of the cassette, the length of the hand is set so that the position of the substrate detection sensor is located on the back side of the back side edge position of the substrate. The substrate transfer robot according to claim 1, wherein the substrate transfer robot is a substrate transfer robot.   9. The auxiliary hand according to claim 1, further comprising an auxiliary hand whose proximal end is supported by the hand holder and shorter in length than the hand, closer to the outside of the hand holder than the hand. Substrate transfer robot.

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